It has become relatively common for individuals to possess a number of different devices through which they communicate. For example, a person may have a home telephone, a wireless telephone, a pager, a personal digital assistant (PDA), and an office telephone to name a few. As the population becomes increasingly mobile, making contact with a person through one of these communication devices has become more difficult.
Call forwarding is one method of addressing this problem. Certain telephone systems allow users to enter another number to which a call is forwarded if not answered by a specified number of rings. This should allow an individual with multiple telephone devices to forward the call to such devices until the telephone at which the individual is located finally rings. However, if several telephones are involved, this approach becomes complicated. Moreover, it requires the calling party to remain on the line for a significant period of time if the call is to be forwarded multiple times. Furthermore it is necessary that call forwarding capabilities exist on each of the individual's telephones. In addition, this approach requires that all telephones involved be reprogrammed each time an individual desires to initiate call forwarding.
A significant drawback to this forwarding strategy is that, in each leg of the forwarded call, the calling party is terminated on the last device or network in the chain. It follows that the final number in the forwarding scheme is responsible for all available enhanced services or voicemail available to the caller. Accordingly, although a call may have been initially placed to an office telephone equipped with voicemail and/or operator assist, all such enhanced services of the corporate network are lost once the call is forwarded off the corporate PBX (e.g., to the user's wireless telephone).
Travel can also exacerbate the difficulty of establishing communication with an individual having access to multiple telephone devices. Upon checking into a hotel, the telephone in a traveler's hotel room becomes available as yet another potential means of contact. Unfortunately, this forces a calling party to decide whether to attempt to contact the traveler through his or her room telephone or other telephone device (e.g., wireless telephone or pager). If the traveler does not answer the called telephone, the calling party then must decide whether to leave a message (unaware of when, or if, the message will be retrieved) or instead attempt to reach the traveler via his or her other telephone.
Likewise, if the traveler is expecting an important call but is unsure whether it will be placed to his room telephone or wireless telephone, the traveler may feel compelled to remain within his room until the call has been received. In addition, if the traveler's wireless telephone does not support certain types of long distance calls (e.g., to various foreign countries), the traveler may be able to place certain types of calls only from his or her hotel room. The same problems arise when the traveler visits another office or enterprise having their own enterprise telecommunications network.
The office telephone is the primary point of contact of most business people. Typically, corporations invest significantly in their office telephone infrastructure, which often includes voicemail, paging and unified messaging systems. In addition, most corporations have negotiated contracts with their telephone carriers (e.g., local and long distance carriers) to ensure that they obtain the lowest possible rates for calls placed via their corporate network. However, because the corporate workforce is becoming increasingly mobile, more business people are using wireless telephones or devices to conduct their business when they are out of the office. This has resulted in corporations spending a larger portion of their telecommunications budget on wireless communications, with far less favorable negotiated rates than the rates of their corporate network. In addition, wireless communication systems often lack the enhanced conveniences (e.g., interoffice voicemail, direct extension dialing, etc.) that corporate users have come to expect in the office environment.
Often times, one must communicate with a particular individual and cannot wait until the individual completes the current call. This is sometimes referred to as Multi-level Precedence and Preemption (MLPP), but is referred to herein as “priority preemption.” Priority preemption, however, is limited to the telephones connected to the enterprise network, which limits the ability of the higher ranking official to contact the appropriate individual (who may also be a high ranking officer or government official) when the need arises. It is desirable to extend the priority preemption capability to wireless and remote devices so that priority users are able to preempt existing communications and communicate with certain individuals even though that individual is using a wireless telephone or other remote device.